[Coral-List] Red Sea Lionfishes

Isabelle Côté imcote at sfu.ca
Wed Sep 24 11:55:24 EDT 2014

Hi Phil, 

I'm just catching up on email and finally got around to yours. 

Living at high density can certainly trigger shifts in behaviour to lessen competition. You would then expect those fish that are the least competitive (e.g., smaller ones) to be the ones doing the shifting. We didn't find any evidence that smaller fish were more likely to be out in the open on unculled reefs. 

My feeling is that the differences in behaviour we report in the PLOS One paper may be temporary responses to diver presence. We don't know whether lionfish on culled reefs become 'permanently' crepuscular. We would have to video their behaviour in the absence of divers to ascertain that. From a control perspective, that distinction doesn't matter - what matters is that the fish are harder to find when divers are there. From an ecological perspective, however, it does matter because permanent crepuscular behaviour changes drastically the native species that lionfish encounter. 



----- Original Message -----

From: "Philip Karp" <pkarp24 at gmail.com> 
To: "Justin Grubich" <justinrg at gmail.com> 
Cc: coral-list at coral.aoml.noaa.gov, "Isabelle Côté" <imcote at sfu.ca>, "Stephanie Green" <stephanie.green at science.oregonstate.edu>, jocelyncurtisquick at ceibahamas.org 
Sent: Saturday, 16 August, 2014 8:38:12 AM 
Subject: Re: Red Sea Lionfishes 


Thanks for sharing. Your finding re the primarily crepuscular browsing behavior of Pterois miles is indeed interesting in the context of lionfish control initiatives in the Western Atlantic. 
As you may know, one of the notable observations about behavior of lionfish in the invaded range is that they are being sighted throughout the day, often in large aggregations. This has been attributed by some to be a function of the absense of predators. 
There is recent evidence of a behavioral shift in some areas. 
A study published earlier this year ( What Doesn't Kill You Makes You Wary? Effect of Repeated Culling on the Behaviour of an Invasive Predator) http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0094248 , Isabelle Cote, et al examined behavior of lionfish populations ( Pterois volitans / miles ) on coral reef patches in the Bahamas. They found that on reefs where culling by divers is being undertaken regularly, the lionfish are becoming crepuscular in their feeding activity, hiding out in crevices during the day and browsing at dawn and dusk, whereas lionfish on reefs where there is no culling taking place were observed to be active throughout the day. I am aware of anecdotal observations of similar behavioral change in other parts of the invaded range where culling is being undertaken regularly. 

Cote et al hypothesized that the change in behavior is a direct result of the culling activity; i.e. the lionfish are adapting to the regular spearing and are becoming wary, hiding during the times of day that the culling typically takes place. 
Given your findings, I’m wondering whether an alternative explanation might be that the daytime feeding activity observed on unculled reefs in the invaded range is a function of the high densities (100+ fish ha –1 in some areas) and associated heightened competition, necessitating more time spent on hunting, and that the change to crepuscular behavior might be a reversion to “normal” behavior as population density is reduced through culling and competition lessens accordingly. 

I’d be interested in your thoughts on this, as well as those of the authors of the PLOS article (I’m copying several of them, for whom I have email addresses, as I’m not sure whether they are subscribed to the Coral-List). 

Whatever the explanation for the behavioral change, it is important, as Cote et al point out, to consider the implications for culling activities and techniques, as these are indeed proving to be effective in reducing lionfish populations on invaded reefs, but may now need to be adjusted in light of what is being learned about how lionfish in the invaded range are adapting.. 
Phil Karp 

Message: 4 
Date: Wed, 13 Aug 2014 15:49:04 -0400 
From: Justin Grubich < justinrg at gmail.com > 
Subject: [Coral-List] Red Sea Lionfishes 
To: " coral-list at coral.aoml.noaa. gov " < coral-list at coral.aoml.noaa. gov > 
Message-ID: < 95274E9D-7E62-458C-9146- D483FE503929 at gmail.com > 
Content-Type: text/plain; charset=us-ascii 

Hello coral-listers, 

For those interested in the lionfish invasion of the Western Atlantic, my colleague and I just published a new paper surveying lionfishes in their native range of the Red Sea. More to 
come as well. 

The link to the abstract is below. 


http://www.int-res.com/ abstracts/meps/v508/p223-232/ 

Dr Isabelle Côté 
Professor of Marine Ecology 
Department of Biological Sciences 
Simon Fraser University 
Burnaby, BC 
V5A 1S6 

tel. +1-778-782-3705 (direct), 782-4475 (secretary) 
fax +1-778-782-3496 

'I am very busy with the Zoology of the Sea; the treasures of the deep to a naturalist are indeed inexhaustible.' 
Charles Darwin, The Voyage of Beagle 


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